Earth Hour 2015

Students place candles in shape of the logo of Earth Hour, at a primary school in Handan, Hebei province, a day before Earth Hour Day, March 27, 2015. Picture taken early March 27. REUTERS/China Daily

/

The colonial aqueduct Arcos da Lapa is pictured during Earth Hour in Rio de Janeiro, March 28, 2015. Lights go off around the world at 8.30 p.m. local time in a show of support for renewable energy during Earth Hour, an event organised since 2007 to promote a sustainable future for the planet. REUTERS/Pilar Olivares

/

London Eye is seen during the Earth Hour in central London March 28, 2015. Lights go off around the world at 8.30 p.m. local time in a show of support for renewable energy during Earth Hour, an event organised since 2007 to promote a sustainable future for the planet. REUTERS/Stefan Wermuth

/

A combination picture shows the colonial aqueduct Arcos da Lapa before (L) and during (R) Earth Hour in Rio de Janeiro, March 28, 2015. Lights go off around the world at 8.30 p.m. local time in a show of support for renewable energy during Earth Hour, an event organised since 2007 to promote a sustainable future for the planet. REUTERS/Pilar Olivares

/

A combination photo shows the Serbian Parliament building before (L) and during the Earth Hour in Belgrade March 28, 2015. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 pm local time, is meant as a show of support for tougher action to confront climate change. REUTERS/Marko Djurica

/

St. Sava church is seen before the Earth Hour in Belgrade March 28, 2015. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 pm local time, is meant as a show of support for tougher action to confront climate change. REUTERS/Marko Djurica

/

A combination picture shows Big Ben and the Houses of Parliament before (top) and during Earth Hour in central London March 28, 2015. REUTERS/Stefan Wermuth

/

A combination picture shows the city hall before (top) and during Earth Hour in Vienna March 28, 2015. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for tougher action to confront climate change. REUTERS/Heinz-Peter Bader

/

A combination picture shows Madrid's Royal Palace before (top) and during (bottom) the Earth Hour in Madrid March 28, 2015. Lights go off around the world at 8.30 p.m. local time in a show of support for renewable energy during Earth Hour, an event organised since 2007 to promote a sustainable future for the planet. REUTERS/Susana Vera

/

A couple stand in front of the "Puente Nuevo" (New Bridge), before Earth Hour in Ronda, southern Spain, March 28, 2015. REUTERS/Jon Nazca

/

Madrid's Royal Palace is seen during the Earth Hour in Madrid March 28, 2015. Lights go off around the world at 8.30 p.m. local time in a show of support for renewable energy during Earth Hour, an event organised since 2007 to promote a sustainable future for the planet. REUTERS/Susana Vera

/

People hold candles near a mock earth planet during the Earth Hour outside Madrid's Royal Palace March 28, 2015. Lights go off around the world at 8.30 p.m. local time in a show of support for renewable energy during Earth Hour, an event organised since 2007 to promote a sustainable future for the planet. REUTERS/Susana Vera

/

The Serbian Parliament building is seen during the Earth Hour in Belgrade March 28, 2015. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 pm local time, is meant as a show of support for tougher action to confront climate change. REUTERS/Marko Djurica

/

The city hall is seen during Earth Hour in Vienna March 28, 2015. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for tougher action to confront climate change. REUTERS/Heinz-Peter Bader

/

A combination photo shows St. Sava church before (L) and during the Earth Hour in Belgrade March 28, 2015. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 pm local time, is meant as a show of support for tougher action to confront climate change. REUTERS/Marko Djurica

/

Combination picture shows the Hungarian parliament building before (top) and during Earth Hour in Budapest, March 28, 2015. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for tougher action to confront climate change. REUTERS/Bernadett Szabo

/

The hill of the Acropolis is pictured during Earth Hour in Athens March 28, 2015. Lights go off around the world at 8.30 p.m. local time in a show of support for renewable energy during Earth Hour, an event organised since 2007 to promote a sustainable future for the planet. REUTERS/Kostas Tsironis

/

People hold balloons with lights inside as they wait for the start of the Earth Hour outside Madrid's Royal Palace March 28, 2015. Lights go off around the world at 8.30 p.m. local time in a show of support for renewable energy during Earth Hour, an event organized since 2007 to promote a sustainable future for the planet. REUTERS/Susana Vera

/

A combination picture shows London Eye before (top) and during the Earth Hour in central London March 28, 2015. Lights go off around the world at 8.30 p.m. local time in a show of support for renewable energy during Earth Hour, an event organised since 2007 to promote a sustainable future for the planet. REUTERS/Stefan Wermuth

/

A combination picture shows the city hall before (top) and during Earth Hour in Vienna March 28, 2015. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for tougher action to confront climate change. REUTERS/Heinz-Peter Bader

/

St. Sava church is seen during the Earth Hour in Belgrade March 28, 2015. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 pm local time, is meant as a show of support for tougher action to confront climate change. REUTERS/Marko Djurica

/

Participants perform aerodance during Earth Hour in Quezon city, metro Manila March 28, 2015. The lights went down in parts of the Philippines on Saturday, as part of a climate change awareness campaign spanning multiple cities around the world. REUTERS/Romeo Ranoco

/

Hong Kong's central financial district's (L-R) Bank of China Tower, Cheung Kong Centre, HSBC headquarters and Standard Chartered Bank are pictured with most of their lights switched off during Earth Hour March 28, 2015. Lights go off around the world at 8.30pm local time in a show of support for renewable energy during Earth Hour, an event organised since 2007 to promote a sustainable future for the planet. REUTERS/Tyrone Siu

/

A general view shows Yintai Centre buildings, with their red light on top turned off, during Earth Hour in Beijing's central business district, March 28, 2015. Lights around the world are switched off to mark Earth Hour to raise awareness about energy consumption. Picture taken with fish eye lens. REUTERS/Kim Kyung-Hoon

/

A combination picture shows the Taipei 101 building before (top) and during Earth Hour in Taipei March 28, 2015. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for tougher action to confront climate change. REUTERS/Pichi Chuang

/

Combination picture shows Yintai Centre buildings before (top) and during Earth Hour, when they turn off the red lights on the tops, in Beijing's central business district, March 28, 2015. Lights around the world are switched off to mark Earth Hour to raise awareness about energy consumption. REUTERS/Kim Kyung-Hoon

/

Participants perform aerodance during Earth Hour in Quezon city, metro Manila March 28, 2015. The lights went down in parts of the Philippines on Saturday, as part of a climate change awareness campaign spanning multiple cities around the world. REUTERS/Romeo Ranoco

/

A general view shows Yintai Centre buildings, with their red lights on top turned off, during Earth Hour in Beijing's central business district, March 28, 2015. Lights around the world are switched off to mark Earth Hour to raise awareness about energy consumption. REUTERS/Kim Kyung-Hoon

/

Leifeng Pagoda is seen behind the West Lake before Earth Hour in Hangzhou, Zhejiang province, March 28, 2015. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for tougher action to confront climate change. REUTERS/Chance Chan